Joomla regallery2のエラー

<b>Warning</b>:  fopen(/xxx/media/display_temp.jpg)
[<a href='function.fopen'>function.fopen</a>]:
failed to open stream: Permission denied in 

<b>/xxx/administrator/components/com_/includes/img.utils.php</b>
 on line <b>912</b><br />
<br />
<b>Warning</b>:  fclose(): supplied argument is not a valid stream resource in 

<b>/xxx/administrator/components/com_rsgallery2/includes/img.utils.php</b>

 on line <b>913</b><br />
<br />
<b>Warning</b>:  imagejpeg()
[<a href='function.imagejpeg'>function.imagejpeg</a>]:
 Unable to open '/xxx/media/display_temp.jpg' for writing in 

<b>/xxx/administrator/components/com_rsgallery2/includes/img.utils.php</b>

 on line <b>914</b><br />